Gaming system and method of varying a jackpot game outcome

ABSTRACT

A jackpot triggering method for symbol-driven jackpot awarding techniques comprises determining the amount of credit bet by a player on the commencement of game play. Whether a substitute symbol substitutes for a particular jackpot symbol varies depending on the amount of credit bet by the player and in turn affects the probability of a jackpot being awarded.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of priority to Australian Provisional Patent Application No. 2008901550, filed on Mar. 31, 2008, entitled “A SYSTEM AND METHOD OF VARYING A JACKPOT GAME OUTCOME”, which is herein incorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to a gaming system and a method of gaming, and particularly, but not exclusively, to a gaming system and method of gaming which varies the outcome of a jackpot game.

BACKGROUND OF THE INVENTION

It is known to provide a gaming system which includes a game controller arranged to randomly display several symbols from a predetermined set of symbols and to determine a game outcome such as a game win based on the displayed symbols. Such gaming systems may commonly be implemented as a stepping machine provided with reels with each reel carrying several symbols of the set, or a video machine wherein selected symbols are displayed on virtual reels on a graphical display device. Win outcomes can occur based on symbols appearing in one or more horizontal lines, diagonal lines, or any other predetermined way.

Many venues employ jackpot controllers for awarding jackpots to one of or more of a plurality of gaming machines participating in the jackpot. Typically, a portion of turnover on each gaming machine is forwarded to a jackpot controller as a contribution. That is, part of each wager goes towards the jackpot. The technique can be implemented within a single gaming machine or may be extended to a so called wide area jackpot where multiple gaming machines (from one or more different venues) contribute to a single jackpot pool.

One common way of awarding a jackpot is a so called “symbol driven” jackpot, where a predetermined symbol pattern or win outcome triggers payment of the jackpot. While such gaming systems provide users with enjoyment, the need exists for alternative gaming systems in order to maintain or increase player enjoyment.

While it is a simple matter to scale the amount of prize return with regard to the amount of credit bet by the player for prizes that are of known value for a winning combination, it is not possible to do this for jackpot prizes, which accumulate over a period of time, or prizes of fixed value, e.g. a car. Jackpot prizes may, for example, depend on a percentage amount of credits entered into a gaming system over a period of time, or even a percentage amount of credits entered into linked gaming machines (linked jackpots) over a period of time. Winning of the jackpot is independent of the amount of credit wagered on any particular win line by a player. This is perceived as being unfair to players who are willing to wager large amounts of credit in order to increase their chances of winning a jackpot.

SUMMARY OF THE INVENTION

In accordance with a first aspect, the present invention provides a jackpot triggering method for symbol jackpots, including, determining the amount of credit bet by a player on the commencement of game play, providing a substitute symbol that operates to substitute for a nominated symbol, and varying whether the substitute symbol will substitute for a jackpot winning symbol dependent on the amount of credit bet by the player, to thereby affect the probability of a jackpot being awarded.

In one embodiment, the nominated symbol is a jackpot winning symbol. In an embodiment, as the amount of credit bet by the player is increased, the probability of the substitute symbol substituting for a jackpot symbol increases.

In one embodiment, the probability of the substitute symbol substituting for a jackpot symbol is directly proportional to the amount of credit bet.

In one embodiment, a plurality of jackpot symbols are provided, each one of the plurality of jackpot symbols being associated with a different jackpot.

In an embodiment, on a player increasing the credit bet on a game, the substitute symbol is varied dependent on the amount of credit bet by the player, to allow the substitute symbol to substitute for a sub-set of the plurality of jackpot symbols.

In one embodiment, as the amount of credit bet by the player is increased, the number of symbols in the subset of the plurality of symbols increases.

In one embodiment, the symbol that may be substituted for a Jackpot symbol is a WILD symbol.

In an embodiment the jackpot is awarded upon determining that a designated jackpot symbol combination is displayed during game play.

In accordance with a second aspect, there is provided a gaming system including a plurality of gaming devices which may participate in a jackpot by making jackpot contributions; and a jackpot controller arranged to: determine the amount of credit bet by a player of each gaming device on the commencement of game play, and varying the type of symbol that may be substituted for a jackpot symbol dependent on the determined amount of credit bet by the player, to thereby affect the probability of a jackpot being awarded.

In an embodiment, the probability of the substitute symbol substituting for a jackpot symbol increases with the amount of credit bet by the player.

In an embodiment, the probability of the substitute symbol substituting for a jackpot symbol is directly proportional to the amount of credit bet by the player.

In an embodiment, a plurality of jackpot symbols are provided, each one of the plurality of jackpot symbols being associated with a different jackpot.

In an embodiment, on a player increasing the credit bet on a game, the jackpot controller is operable to vary the substitute symbol dependent on the amount of credit bet to thereby allow the substitute symbol to substitute for a sub-set of the plurality of jackpot symbols.

In an embodiment, the number of symbols in the sub-set of the plurality of symbols increases with the amount of credit bet by the player.

In an embodiment, the symbol that is substituted for a jackpot symbol is a wild symbol.

In accordance with a third aspect, the present invention provides a controller for a gaming device operable to provide, during game play, a substitute symbol that may substitute for a nominated symbol, the controller arranged to: determine an amount of credit bet by a player of the gaming device on commencement of game play, and vary whether the substitute symbol will substitute for a jackpot winning symbol dependent on the determined credit amount, to thereby affect the probability of a jackpot being awarded to the player.

In an embodiment the controller implements an outcome determiner module for determining the amount of credit bet by the player.

In an embodiment the controller further includes an award module operable to award the jackpot upon determining that a designated jackpot symbol combination is displayed during game play.

In accordance with a fourth aspect, there is provided computer program code which when executed implements the method in accordance with the first aspect of the invention.

In accordance with a fifth aspect, there is provided a computer readable medium including the program code in accordance with the fourth aspect of the invention.

In accordance with a sixth aspect, there is provided a data signal including the program code in accordance with a fifth aspect of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, further aspects, and advantages of the present invention will become apparent from the following description of embodiments thereof, by way of example only, with reference to the accompanying drawings. Also, various embodiments of the aspects described in the preceding paragraphs will be apparent from the appended claims, the following description and/or the accompanying drawings. It should be understood, however, that the present invention is not limited to the arrangements and instrumentality shown in the attached drawings.

FIG. 1 is a schematic block diagram of core components of a gaming system in accordance with an embodiment of the present invention;

FIG. 2 is a diagrammatic representation of a gaming system in accordance with an embodiment of the present invention with the gaming system implemented in the form of a stand alone gaming machine;

FIG. 3 is a schematic block diagram of operative components of the gaming machine shown in FIG. 2;

FIG. 4 is a schematic block diagram of components of a memory of the gaming machine shown in FIG. 2;

FIG. 5 is a schematic diagram of a gaming system in accordance with an alternative embodiment of the present invention with the gaming system implemented over a network;

FIG. 6 is a schematic diagram of functional components of a gaming system in accordance with an embodiment of the present invention;

FIG. 7 is a flow diagram illustrating operation of a gaming system in accordance with an embodiment of the present invention; and

FIGS. 8 a and 8 b are representations of example displays generated by a gaming system in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF AN EMBODIMENT

Embodiments provide a jackpot triggering method for symbol-driven jackpots. The method determines the amount of credit bet by a player on the commencement of game play. There is provided a substitute symbol that operates to substitute for nominated symbol. Whether the substitute symbol substitutes for a jackpot winning symbol varies depending on the amount of credit bet by the player. This affects the probability of a jackpot being awarded.

The gaming system may be provided in a number of different forms.

In a first form, a stand alone gaming machine is provided wherein all or most components implementing the game are present in a player operable gaming machine.

In a second form, a distributed architecture is provided wherein some of the components implementing the game are present in a player operable gaming machine and some of the components implementing the game are located remotely relative to the gaming machine. For example, a “thick client” architecture may be used wherein part of the game is executed on a player operable gaming machine and part of the game is executed remotely, such as by a gaming server; or a “thin client” architecture may be used wherein most of the game is executed remotely such as by a gaming server and a player operable gaming machine is used only to display audible and/or visible gaming information to the player and receive gaming inputs from the player.

However, it will be understood that other arrangements are envisaged. For example, an architecture may be provided wherein a gaming machine is networked to a gaming server and the respective functions of the gaming machine and the gaming server are selectively modifiable. For example, the gaming system may operate in stand alone gaming machine mode, “thick client” mode or “thin client” mode depending on the game being played, operating conditions, and so on. Other variations will be apparent to persons skilled in the art.

Irrespective of the form, the gaming system includes several core components. At the broadest level, the core components are a player interface 50 and a game controller 60 as illustrated in FIG. 1. The player interface is arranged to enable manual interaction between a player and the gaming system and for this purpose includes the input/output components for the player to enter instructions and play the game.

Components of the player interface may vary from embodiment to embodiment but will typically include a credit mechanism 52 to enable a player to input credits and receive payouts, one or more displays 54 and a game play mechanism 56 that enables a player to input game play instructions.

The game controller 60 is in data communication with the player interface and typically includes a processor 62 that processes the game play instructions in accordance with game play rules and outputs game play outcomes to the display. Typically, the game play instructions are stored as program code in a memory 64 but can also be hardwired. Herein the term “processor” is used to refer generically to any device that can process game play instructions in accordance with game play rules and may include: a microprocessor, microcontroller, programmable logic device or other computational device, a general purpose computer (e.g. a PC) or a server.

A gaming system in the form of a stand alone gaming machine 10 is illustrated in FIG. 2. The gaming machine 10 includes a console 12 having a display 14 on which is displayed representations of a game 16 that can be played by a player. A mid-trim 20 of the gaming machine 10 houses a bank of buttons 22 for enabling a player to interact with the gaming machine, in particular during game play. The mid-trim 20 also houses a credit input mechanism 24 which in this example includes a coin input chute 24A and a bill collector 24B. Other credit input mechanisms may also be employed, for example, a card reader for reading a smart card, debit card or credit card. A player marketing module may be provided having a reading device may also be provided for the purpose of reading a player tracking device, for example as part of a loyalty program. The player tracking device may be in the form of a card, flash drive or any other portable storage medium capable of being read by the reading device.

A top box 26 may carry artwork 28, including for example pay tables and details of bonus awards and other information or images relating to the game. Further artwork and/or information may be provided on a front panel 29 of the console 12. A coin tray 30 is mounted beneath the front panel 29 for dispensing cash payouts from the gaming machine 10.

The display 14 shown in FIG. 2 is in the form of a video display unit, particularly a cathode ray tube screen device. Alternatively, the display 14 may be a liquid crystal display, plasma screen, any other suitable video display unit, or the visible portion of an electromechanical device. The top box 26 may also include a display, for example a video display unit, which may be of the same type as the display 14, or of a different type.

FIG. 3 shows a block diagram of operative components of a typical gaming machine which may be the same as or different to the gaming machine of FIG. 2.

The gaming machine 100 includes a game controller 101 having a processor 102. Instructions and data to control operation of the processor 102 are stored in a memory 103, which is in data communication with the processor 102. Typically, the gaming machine 100 will include both volatile and non-volatile memory and more than one of each type of memory, with such memories being collectively represented by the memory 103.

The gaming machine has hardware meters 104 for purposes including ensuring regulatory compliance and monitoring player credit, an input/output (I/O) interface 105 for communicating with peripheral devices of the gaming machine 100. The input/output interface 105 and/or the peripheral devices may be intelligent devices with their own memory for storing associated instructions and data for use with the input/output interface or the peripheral devices. A random number generator module 113 generates random numbers for use by the processor 102. Persons skilled in the art will appreciate that the reference to random numbers includes pseudo-random numbers.

In the example shown in FIG. 3, a player interface 120 includes peripheral devices that communicate with the game controller 101 include one or more displays 106, a touch screen 107, a card and/or ticket reader 108, a printer 109, a bill acceptor and/or coin input mechanism 110 and a coin output mechanism 111. Additional hardware may be included as part of the gaming machine 100, or hardware may be omitted based on the specific implementation.

In addition, the gaming machine 100 may include a communications interface, for example a network card 112. The network card may, for example, send status information, accounting information or other information to a central controller, server or database and receive data or commands from the central controller, server or database.

FIG. 4 shows a block diagram of the main components of an exemplary memory 103. The memory 103 includes RAM 103A, EPROM 103B and a mass storage device 103C. The RAM 103A typically temporarily holds program files for execution by the processor 102 and related data. The EPROM 103B may be a boot ROM device and/or may contain some system or game related code. The mass storage device 103C is typically used to store game programs, the integrity of which may be verified and/or authenticated by the processor 102 using protected code from the EPROM 103B or elsewhere.

It is also possible for the operative components of the gaming machine 100 to be distributed, for example input/output devices 106,107,108,109,110,111 to be provided remotely from the game controller 101.

FIG. 5 shows a gaming system 200 in accordance with an alternative embodiment. The gaming system 200 includes a network 201, which for example may be an Ethernet network. Gaming machines 202, shown arranged in three banks 203 of two gaming machines 202 in FIG. 5, are connected to the network 201. The gaming machines 202 provide a player operable interface and may be the same as the gaming machines 10,100 shown in FIGS. 2 and 3, or may have simplified functionality depending on the rules and/or guidelines for implementing game play. While banks 203 of two gaming machines are illustrated in FIG. 5, banks of one, three or more gaming machines are also envisaged.

One or more displays 204 may also be connected to the network 201. The displays 204 may, for example, be associated with one or more banks 203 of gaming machines. The displays 204 may be used to display representations associated with game play on the gaming machines 202, and/or used to display other representations, for example promotional or informational material.

In a thick client embodiment, game server 205 implements part of the game played by a player using a gaming machine 202 and the gaming machine 202 implements part of the game. With this embodiment, as both the game server and the gaming device implement part of the game, they collectively provide a game controller. A database management server 206 may manage storage of game programs and associated data for downloading or access by the gaming devices 202 in a database 206A. Typically, if the gaming system enables players to participate in a Jackpot game, a Jackpot server 207 will be provided to carry out the accounting in respect of the Jackpot game. A loyalty program server 212 may also be provided.

In a thin client embodiment, game server 205 implements most or all of the game played by a player using a gaming machine 202 and the gaming machine 202 essentially provides only the player interface. With this embodiment, the game server 205 provides the game controller. The gaming machine will receive player instructions, pass these to the game server which will process them and return game play outcomes to the gaming machine for display. In a thin client embodiment, the gaming machines could be computer terminals, e.g. PCs running software that provides a player interface operable using standard computer input and output components.

Servers are also typically provided to assist in the administration of the gaming network 200, including for example a gaming floor management server 208, and a licensing server 209 to monitor the use of licenses relating to particular games. An administrator terminal 210 is provided to allow an administrator to run the network 201 and the devices connected to the network.

The gaming network 200 may communicate with other gaming systems, other local networks, for example a corporate network, and/or a wide area network such as the Internet, for example through a firewall 211.

Persons skilled in the art will appreciate that in accordance with known techniques, functionality at the server side of the network may be distributed over a plurality of different computers. For example, elements may be run as a single “engine” on one server or a separate server may be provided. For example, the game server 205 could run a random generator engine. Alternatively, a separate random number generator server could be provided. Further, persons skilled in the art will appreciate that a plurality of games servers could be provided to run different games or a single game server may run a plurality of different games based on the terminals.

In yet a further alternative embodiment (not shown) one of the individual gaming machines 202 is capable of acting as the server providing network gameplay and awarding functionality for the other gaming machines 202. In such an embodiment, the gaming machines not acting as the server would be designated as slaves (i.e. the clients).

The embodiment may be implemented in relation to a spinning reel type game. Gaming systems for implementing games that involve a display of spinning reels as part of the display of the outcome of a game have either a video display or a mechanical display, these later machines most usually being “stepper” machines which have a separate motor for each reel. However, persons skilled in the art will appreciate that the invention can be implemented in respect if other forms of games, including; card games; ball draw games (e.g. bingo or keno); dice games; and pin and ball games.

In some implementations the game controllers of such gaming machines select symbols by employing a stop determining function that randomly determines the stop position for each reel. For example, if there are five reels, each having twenty symbols, the stop determining function might determine that the stop positions are positions: 3, 13, 7, 9 and 17. The spinning of the reels is then controlled so that each symbol comes to a stop in the same row, typically a predetermined row in a “window” visible to the player on the display that which corresponds to a player playing a single win line. When a reel stops, the symbols will be in one of a plurality of possible symbol positions for that reel relative to the stop position.

Spinning reel type games typically allow a player to select how many win lines of a plurality of win lines they will play in each game—i.e. a minimum of one win line up to the maximum number of win lines allowed by the game. Persons, skilled in the art, will appreciate that in other embodiments, the player may select a number of reels to play. Each win line is formed by a set of symbol positions consisting of one symbol position from each reel. That is, a predetermined symbol position of each reel is assigned to a win line. The symbol positions that constitute each of the win lines are usually advertised to the player by markings on the display or diagrams showing the symbol positions that correspond to each win line. Some of the win lines will be horizontal or diagonal lines but others may be non-linear combinations of symbols. Typically, the win lines will be constituted by symbol positions in the visible window. A game outcome is determined based on the symbols on the win lines and a prize table that specifies awards.

In some gaming machines, a “jackpot” may be offered. The jackpot is a large or special prize that may be awarded at a random time throughout game play, and may or may not be conditional on the outcome of the main game. Many venues employ jackpot controllers for awarding jackpots to one of or more of a plurality of gaming machines participating in the jackpot. Typically, a portion of turnover on each gaming machine is forwarded to a jackpot controller as a contribution. That is, part of each wager from each gaming machine is forwarded to a central jackpot controller for contributing to a jackpot prize pool (from which the jackpot prize is awarded). The technique can be implemented within a single gaming machine, or may be extended to a so called wide area jackpot where multiple gaming machines (from one or more different venues) contribute to a single jackpot pool. One common way of determining a jackpot entitlement is a so called “symbol driven” jackpot, where a predetermined symbol pattern or win outcome triggers the jackpot.

There may also be provided a number of different symbol driven jackpots. For example, three different “levels” of symbol driven jackpot may be offered, such as a mini jackpot (typically in the order of a hundred dollars), a midi jackpot (typically in the order of a thousand dollars) and a maxi jackpot (typically in the order of tens of thousands of dollars). Each symbol driven jackpot is denoted by a different symbol. For example, one type of symbol may be associated with a mini jackpot (say, a “Jackpot1” symbol), another type of symbol may be associated with a midi jackpot (say, a “Jackpot2” symbol), and yet be associated with a maxi jackpot (say, a “Jackpot3” symbol). In this manner, a player can instantly recognise which type of jackpot they have won, if the correct combination of jackpot symbols appears at the conclusion of game play.

The symbol driven jackpot, in the presently described embodiment, is operated and controlled by the game controller 60, which is shown in more detail in FIG. 6. It will apparent that the processor 62 implements a number of modules, namely random number generator module 621, symbol selector module 622, outcome determiner module 623, award determiner module 624, sequence monitoring module 625, display controller module 626 and jackpot controller 627, each of which may utilise data stored in memory 64. Persons skilled in the art will appreciate that not all modules need be implemented by processor 62. For example, the random number generator module 621 could be implemented by a separate circuit or by a random number generator server.

In the embodiment, the award determiner module 624 determines when a player is entitled to an award. The award, in some instances, may be triggered by a so-called “symbol jackpot”. That is, when a predetermined arrangement of jackpot winning symbols is displayed on the display, the player is awarded a jackpot prize. The jackpot prize may be an internal jackpot particular to a single gaming machine or may be extended to a so called wide area jackpot where multiple gaming machines (from one or more different venues) contribute to a single jackpot pool. Where the jackpot prize is a wide area jackpot, it will be understood that the jackpot controller may reside outside a particular gaming machine (e.g. one of the serves illustrated in FIG. 5).

During each game of a sequence, the symbol selector 622 selects the symbols to appear based on symbol data 641 which specifies the available symbols. The symbols are selected by the symbol selector 622 using a random number obtained from the random number generator 621. The outcome determiner module 623 determines the game outcomes and their associated prizes based on the number of win lines the player is playing and the symbol combinations. Persons skilled in the art will also appreciate that the game outcomes and their associated prizes are displayed on the display 54, or under control of the display controller 626.

The award determiner 624 is also employed to keep track of the total award. Where a jackpot is awarded, the award determiner 624 may interface with the jackpot controller 627, so that when a jackpot is won, the jackpot award can be determined and communicated to the player, based on data received from the jackpot controller 627. The jackpot controller 627 may be internal to a single gaming machine, or may be an external device arranged to interface with a plurality of gaming machines (as previously described).

The method 700 of an embodiment of the invention is summarised in FIG. 700. At step 710 it is determined game sequence should commence (which usually occurs due to player input, such as selecting the amount of credits the player wishes to bet). At step 720, the amount of credit bet by the player is noted by the outcome determiner module 623. The game controller 60 then carries out a game 730. The game may be carried out in any conventional manner, such as the manner described previously. In the embodiment, the symbol set includes a “WILD” symbol, which is a symbol that may substitute for one or more other nominated symbols. That is, in certain circumstances, which are described in more detail later, the WILD symbol is considered to be equivalent to a sub-set of other symbols, such that a WILD symbol is “equivalent” to any one of a sub-set of predetermined symbols. As such, the WILD symbol can be used to “substitute” for a symbol, to thereby form a winning combination. In the embodiment described herein, the WILD symbol can substitute for one or more “Jackpot” symbols.

At step 740, the outcome determiner module 623 determines whether any WILD symbols have been displayed, and if so, whether the WILD symbol can substitute for a Jackpot symbol, such that the combination would result in a predetermined jackpot symbol pattern being won. If a winning combination is found, then at step 750, the jackpot controller 627 is interrogated to determine the jackpot prize, and the total award is paid to the player at step 760.

The manner and circumstances in which a WILD symbol may substitute for a Jackpot symbol is now described in more detail, with reference to FIGS. 8 a and 8 b, which illustrate an embodiment of the invention. The example as shown with reference to FIGS. 8 a and 8 b has been simplified to aid clarity. It will be understood that “real life” examples may be more complex, but continue to embody the underlying inventive concept. In the example, the reel game only pays on the 3 horizontal pay lines (referred to as the top row 802, middle row 804 and bottom row 806 respectively). That is, a winning combination is only formed if a correct combination of symbols appears together on any one horizontal line. Moreover, all pay patterns are left to right.

The rules of the game are such that the Jackpot is won if five of any one of the jackpot winning symbols appear in one line of the reel display 800. That is, a player wins the Jackpot if either 5 “JackPot1” symbols appear in one line, 5 “JackPot2” symbols appear in one line, 5 “JackPot3” symbols appear in one line, or 5 “JackPot4” symbols appear in one line. For the purpose of this illustrative example, it is assumed that there are four different Jackpots, each associated with a different jackpot prize.

The sub-set of symbols that the WILD symbol can substitute for is dependent on the number of credits bet by the player. In the illustrated example, the relationship between the number of credits bet and the sub-set of Jackpot symbols that the WILD symbol can substitute for is linear (i.e. if a player bets one credit, the WILD symbol only substitutes for one type of jackpot symbol; if the player bets two credits, the WILD symbol can substitute for two types of jackpot symbols, etc.). This relationship is shown below with reference to table 1:

TABLE 1 Relationship between bet size and WILD substitute Bet size (credit) WILD substitutes for: 1 Jackpot4 2 Jackpot4, Jackpot3 3 Jackpot4, Jackpot3, Jackpot2  4+ Jackpot4, Jackpot3, Jackpot2, Jackpot1

With reference to FIG. 8 a, a player decides to play a reel game and bets a total of one (1) credit per line. A WILD symbol may also substitute for a Jackpot symbol. That is, where a WILD symbol appears on a line, it may be considered to be “equivalent” to a Jackpot symbol.

In accordance with the embodiment, when a player places a bet of one credit per line, the WILD symbol (i.e. the symbol that may substitute for other symbols) will only substitute for the “JackPot4” symbol.

Therefore, with reference to the reel window 800 shown in FIG. 8 a, if the player receives a combination (across 3 lines) of:

Top Row: three “JackPot1” symbols and one “Q” and “WILD” symbol; Middle row: four “JackPot3” symbols and one “WILD” symbol;

Bottom row: No Jackpot Symbols.

Then the player does not win the Jackpot, as the WILD symbol can only substitute for the “Jackpot 4” symbol. That is, as all four symbols in the Middle Row 802 are “Jackpot3” symbols, the WILD symbol cannot be combined with the Jackpot3 symbols to form a winning combination. If however, the player had bet two (2) credits, then the WILD symbol would also have substituted for the “Jackpot3” symbol, thereby causing the player to win the Jackpot on the middle row.

With reference to FIG. 8 b, the player now begins a new game, and chooses to bet three (3) credits per line. As the player has increased their credit bet, the WILD symbol, if it appears, is now capable of substituting for “JackPot3”, “JackPot4” and “JackPot5”. Therefore, if the player receives the combination shown in FIG. 8 b, namely:

Top Row: three “JackPot1” symbols and one “WILD” and “Q” symbol; Middle Row: four “JackPot1” symbols and one “Q” symbol; and Bottom Row: three “JackPot2” and two “WILD” symbols;

Then the player has won the Jackpot, as the WILD symbols can substitute for the symbol “JackPot2” on the bottom row 806. If the player had bet one (1) credit or two (2) credits, they would not have won the Jackpot, as the WILD symbol would only have substituted for the symbol “JackPot4” or the symbols “Jackpot 4” and “Jackpot 3” respectively.

The embodiment described herein provides a jackpot award method and system that provides a direct link between the amount bet by a player and the probability of winning a jackpot. This increases player interest and allows the player to control the “risk” associated with winning a jackpot. That is, a player will realise that when they bet more per game, they have a higher chance of winning the jackpot. Conversely, if the player is risk-averse, they can decrease their bet per game, yet still retain a chance of winning the jackpot.

It will be understood that while the embodiment described herein describes a method where there is a direct proportional link between the number of credits bet and the number of Jackpot symbols for which WILD may substitute, this embodiment is merely a simplified example. Variations such as a logarithmic link, an exponential link, or any other type of “link” may be utilised.

For example, the WILD symbol may only substitute for each additional Jackpot symbol for every 5 additional credits bet, every 10 additional credits bet, etc. Alternatively, as each jackpot may have vastly different values (e.g. “Jackpot4” may only have a value in the order of hundreds of dollars, whereas “Jackpot2” may have a value in the order of tens of thousands of dollars), an embodiment of the invention requires a player to substantively increase their bet size in order to cause the WILD symbol to substitute for a higher value Jackpot symbol. For example, a player may only have to bet 5 credits to cause the WILD symbol to substitute for Jackpot4 (worth hundreds of dollars), but may have to bet 50 credits to cause the WILD symbol to substitute for Jackpot2 (worth tens of thousands of dollars). This in turn creates a link in the player's mind between the amount bet and the possible reward. That is, a player will realise that if they wish to win a large jackpot, they can increase their chance of doing so by betting a larger amount. This is in direct contrast to traditional jackpots, which are won at “random” times and are independent of the amount bet by a player. Any suitable arrangement of linking credits bet to the probability of winning a jackpot may be devised, depending on how an operator believes the player is best incentivised.

Moreover, in an alternative embodiment, the link may be between the bet size and the number of WILD symbols that can be substituted in any given line. That is, for example, where there is only one “Jackpot” symbol, the WILD symbol may only be substituted for a Jackpot symbol a given number of times in any one line. This is best explained by reference to Table 2:

Bet size (credit) WILD substitutes for Jackpot: 1 One (1) Jackpot symbol 2 Two (2) Jackpot symbols 3 Three (3) Jackpot symbols  4+ Four (4) Jackpot symbols

For example, returning to FIG. 8 b, where:

Top Row: three “JackPot1” symbols and one “WILD” and “Q” symbol; Middle Row: four “JackPot1” symbols and one “Q” symbol; and Bottom Row: three “JackPot2” and two “WILD” symbols;

Applying the logic of the alternative embodiment, if the player has bet two (2) credits, then the player has won the Jackpot, as the WILD symbol can substitute for the symbol “JackPot2” twice in any given line. However, if the player had bet one (1) credit, they do not win the Jackpot, as the WILD symbol can only substitute for the symbol “JackPot2” once. That is, the second WILD symbol cannot be used to make a combination of five “Jackpot2” symbols. In other words, there may be a link between the number of credits bet by the player, and the number of times a WILD symbol may be substituted for a Jackpot symbol in any given line.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. Several embodiments are described above with reference to the drawings. These drawings illustrate certain details of specific embodiments that implement the systems and methods and programs of the present invention. However, describing the invention with drawings should not be construed as imposing on the invention any limitations associated with features shown in the drawings. It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.

The present invention contemplates methods, systems and program products on any electronic device and/or machine-readable media suitable for accomplishing its operations. Certain embodiments of the present invention may be implemented using an existing computer processor and/or by a special purpose computer processor incorporated for this or another purpose or by a hardwired system, for example.

Embodiments within the scope of the present invention include program products comprising machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media that can be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media may comprise RAM, ROM, PROM, EPROM, EEPROM, Flash, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer or other machine with a processor. When information is transferred or provided over a network or another communications connection (either hardwired, wireless, or a combination of hardwired or wireless) to a machine, the machine properly views the connection as a machine-readable medium. Thus, any such a connection is properly termed a machine-readable medium. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions comprise, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions. 

1. A jackpot triggering method for symbol jackpots, comprising, determining the amount of credit bet by a player on the commencement of game play, providing a substitute symbol that operates to substitute for a nominated symbol, and varying whether the substitute symbol will substitute for a jackpot winning symbol dependent on the amount of credit bet by the player, to thereby affect the probability of a jackpot being awarded.
 2. A jackpot triggering method in accordance with claim 1, wherein, as the amount of credit bet by the player is increased, the probability of the substitute symbol substituting for a jackpot symbol increases.
 3. A jackpot triggering method in accordance with claim 2, wherein the probability of the substitute symbol substituting for a jackpot symbol is directly proportional to the amount of credit bet.
 4. A jackpot triggering method in accordance with claim 1, wherein, a plurality of jackpot symbols are provided, each one of the plurality of jackpot symbols being associated with a different jackpot.
 5. A jackpot triggering method in accordance with claim 4, wherein, on a player increasing the credit bet on a game, the substitute symbol is varied dependent on the amount of credit bet by the player, to allow the substitute symbol to substitute for a sub-set of the plurality of jackpot symbols.
 6. A jackpot triggering method in accordance with claim 5, wherein, as the amount of credit bet by the player is increased, the number of symbols in the subset of the plurality of symbols increases.
 7. A jackpot triggering method in accordance with claim 1, wherein the symbol that may be substituted for a Jackpot symbol is a WILD symbol.
 8. A jackpot triggering method in accordance with claim 1, wherein the jackpot is awarded upon determining that a designated jackpot symbol combination is displayed during game play.
 9. A gaming system comprising a plurality of gaming devices which may participate in a jackpot by making jackpot contributions; and a jackpot controller arranged to: determine the amount of credit bet by a player on the commencement of game play, and vary the type of symbol that may be substituted for a jackpot winning symbol dependent on the determined amount of credit bet by the player, to thereby effect the probability of a jackpot being awarded to the player.
 10. A gaming system in accordance with claim 9, wherein the probability of the substitute symbol substituting for a jackpot symbol increases with the amount of credit bet by the player.
 11. A gaming system in accordance with claim 9, wherein the probability of the substitute symbol substituting for a jackpot symbol is directly proportional to the amount of credit bet by the player.
 12. A gaming system in accordance with claim 9, wherein a plurality of jackpot symbols are provided, each one of the plurality of jackpot symbols being associated with a different jackpot.
 13. A gaming system in accordance with claim 11, wherein on a player increasing the credit bet on a game, the jackpot controller is operable to vary the substitute symbol dependent on the amount of credit bet to thereby allow the substitute symbol to substitute for a sub-set of the plurality of jackpot symbols.
 14. A gaming system in accordance with claim 13, wherein the number of symbols in the sub-set of the plurality of symbols increases with the amount of credit bet by the player.
 15. A gaming system in accordance with claim 9, wherein the symbol that is substituted for a jackpot symbol is a WILD symbol.
 16. A controller for a gaming device operable to provide, during game play, a substitute symbol that may substitute for a nominated symbol, the controller arranged to: determine an amount of credit bet by a player of the gaming device on commencement of game play, and vary whether the substitute symbol will substitute for a jackpot winning symbol dependent on the determined credit amount, to thereby affect the probability of a jackpot being awarded to the player.
 17. A controller in accordance with claim 16, further comprising an award module operable to award the jackpot upon determining that a designated jackpot symbol combination is displayed during game play.
 18. A computer readable medium comprising computer program code which when executed implements a jackpot triggering method for symbol jackpots, comprising, determining the amount of credit bet by a player on the commencement of game play, providing a substitute symbol that operates to substitute for a nominated symbol, and varying whether the substitute symbol will substitute for a jackpot winning symbol dependent on the amount of credit bet by the player, to thereby affect the probability of a jackpot being awarded.
 19. A computer readable medium in accordance with claim 18, wherein, as the amount of credit bet by the player is increased, the probability of the substitute symbol substituting for a jackpot symbol increases.
 20. A computer readable medium in accordance with claim 19, wherein the probability of the substitute symbol substituting for a jackpot symbol is directly proportional to the amount of credit bet. 